@book{1156,
	author = {Percival, Fred. and Association for Educational and Training Technology.},
	title = {Distance learning and evaluation /},
	publisher = {Kogan Page ;},
	year = {1981.},
	address = {London :},
	note = {Proceedings of the Association's fifteenth annual conference, Aberdeen, 31 March to 3 April, 1981.}
}